Autodesk Mechanical Desktop has been discontinued and starting with the 2010 release is no longer included with any Autodesk Inventor product.
To open Mechanical Desktop files in Inventor 2010 make sure to leave the MDT 2009 installation on your computer.
If you are a previously licensed user of Mechanical Desktop software and have uninstalled Mechanical Desktop 2009 or are installing Inventor 2010 on a new computer then you will need to download new installation files that are compatible with Inventor 2010.
The new installer for AutoCAD Mechanical Desktop 2009 is provided by a self-contained installation file that you can download here. Or, previously licensed users can also request DVD media at no additional charge*.
Please answer the following questions and enter your Inventor serial number below. You will then receive access to a page where you can download the software or order a DVD. Note that Autodesk Mechanical Desktop 2009 is available only to customers who have purchased Autodesk® Inventor® Suite, Autodesk® Inventor® Suite for Simulation, Autodesk® Inventor® Suite for Routed Systems or Autodesk® Inventor® Professional.
*Free products are subject to the terms and conditions of the end-user license agreement that accompanies download of the software.